What is a high vaulted pallet? I am not sure but I would think if you are blowing it correctly then it would give your call a unique sound. You pallet plays a part in it but being able to control your air is really the main part of calling. If your pallet gets in the way of that then you may have some problems. Learning to stop the air is the first step. Good luck.

Get yourself a couple of videos on calling ducks, there are quite a few out there that are good. Controlling air and where you originate the effort from is important. Hold your tongue behind your lower teeth and call from the back of your mouth, down by your throat. A good analogy is if you want to clear a foggy mirror you blow from the front of your mouth, if you want to fog up a mirror - you blow from the back of your mouth; that is where you want to call from. And, practice, practice...

If I understand correctly about what your high pallet. That would mean you would have a larger mouth cavity than me or MR. average. Right? So what you are asking is will that effect your calling? I don't know I would think that you could still move the tongue arch forward and back in your mouth effectively changing the cavity size as long as you can still touch in turn air on and off with the arch of the tongue against the roof of your mouth. You may have to tune a call a little differant or something than the average guy. I don't see where it would be to much of a problem. If I don't understand your condition fully please explain it to me this is interesting to me.

i would say it would help you from squeaking or overpressurizing the call. you want to keep a large cavity when blowing a call or else it will squeak. like bret said, you might have to tune it a little different. ( i would guess a little higher pitched than the normal person). but other than that i dont see much problem